During June the two Gun Carrier Companies were definitely converted into Supply Companies and were attached to the 3rd and 5th Brigades. At the battle of Hamel, on July 4, four of these machines did excellent work, carrying forward between twenty and twenty-five tons of R.E. material and dumping this a few hundred yards behind the final objective within half an hour of this objective being captured. These machines were driven by four officers and sixteen men, and had the material they transported been brought up by carrier parties at least 1,200 men would have been required; in man-power alone these four machines thus saved 1,184 soldiers, or approximately two infantry battalions at battle strength.
On arrival in France the 1st and 2nd Supply Companies were posted to the 1st and 4th Tank Brigades, and the 3rd, 4th, and 5th were sent to Blingel Camp, in the Bermicourt area, where good facilities existed for tank driving and maintenance. At about the end of July the 3rd and 5th Companies were equipped with Mark IV supply tanks, and female Mark IV machines fitted with a sledge equipment.
At the beginning of August the distribution of the various supply units was as follows:
| No. 1 Gun Carrier Company | 5th Tank Brigade. |
| No. 2 Gun Carrier Company | 3rd Tank Brigade. |
| No. 1 Tank Supply Company | 1st Tank Brigade. |
| No. 2 Tank Supply Company | 4th Tank Brigade. |
| No. 3 Tank Supply Company | Blingel Camp. |
| No. 4 Tank Supply Company | 2nd Tank Brigade. |
| No. 5 Tank Supply Company | Blingel Camp. |
All these companies, less No. 1 Tank Supply Company and No. 2 Gun Carrier Company, took part in the battle of Amiens.
No. 1 Gun Carrier Company suffered an unfortunate experience on August 7. It had moved forward to an orchard on the western side of Villers Bretonneux, each of its machines being loaded up with explosives of various kinds. A shell fired from a German battery in the vicinity of Chipilly set fire to one of the camouflage nets, and the result of this was that though six out of the twenty-two machines got away the remaining sixteen were blown up, the explosion being terrific.
The 3rd Tank Supply Company was allotted to the Canadian Corps to carry forward infantry supplies such as grenades, S.A.A., and drinking water. The female Mark IV. tanks equipped with sledges were attached to the Canadian Engineers for the purpose of bringing forward material in order to repair the bridges over the Luce river. Owing to weak cables this operation proved a failure, most of these machines breaking down before they had covered a mile.
The policy which was first adopted of attaching a section of six supply tanks to each battalion did not work well, the Company Headquarters was usually left in the air, and soon lost touch with its sections. In order to remedy this defect from August 9 onwards company commanders were instructed to establish “report centres” well in advance of the battlefield. These centres were “baited” by sending the mails there; to obtain news from home it was consequently necessary for section commanders to send runners in to fetch them; by this means touch with the Company Headquarters was automatically maintained.[29]
In the battles north of the Somme, commencing on August 21, much useful work was carried out, the tank-drivers having by now become thoroughly expert in driving and maintenance. The sections were now properly brigaded, each company being looked upon as a unit and not as a mere headquarters for four separate units. Proper telephonic communication was now established between the sections and the company, and consequently much time was saved not only within the company itself but by the various units it was supplying.